Surgical tissue collection bag

ABSTRACT

An improved surgical dilator extractor is introduced into the abdominal cavity through a trocar cannula and expanded, forming a tissue receiving space, at the distal end. The tissue receiving space is enlarged by passing a grasper through a lumen of the dilator extractor to interact with a guide surface on the interior of dilator extractor to expand a dilator portion having a single leaf beyond the natural resiliency of the leaf. The tissue being extracted is then manipulated into the space with the grasper. The tissue is then removed from the cavity by the surgeon applying a force onto the dilator extractor that insures the elongation of the tissue and temporarily dilates the entry wound to the extent necessary for the tissue to be removed. Alternative embodiments of the surgical dilator extractor and related instrument tool sets and methods for the use thereof also are disclosed.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/802,032, filed May 28, 2010 (now U.S. Pat. No. 8,466,659); which is acontinuation of U.S. application Ser. No. 11/430,431, filed May 9, 2006(now abandoned); which is a divisional of U.S. application Ser. No.10/680,973, filed Oct. 7, 2003 (now U.S. Pat. No. 7,041,055); whichclaims the benefit of U.S. Provisional Application No. 60/416,665, filedOct. 7, 2002; U.S. Provisional Application Nos. 60/424,752; 60/424,754;and 60/424,755, each filed Nov. 8, 2002; U.S. provisional ApplicationNos. 60/425,506; 60/425,522; and 60/425,523, each filed Nov. 12, 2002;and U.S. Provisional Application No. 60/439,759, filed Jan. 13, 2003;all of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention relates generally to mechanical devices andmethods used in laparoscopic surgical procedures to remove organs andexcised tissue from internal body cavities.

It will be appreciated by those skilled in the art that the use of bagsor pouches to remove organs and large tissue specimen duringlaparoscopic surgical procedures is well known. As described, forexample, in U.S. Pat. No. 5,147,371 a pouch is introduced into theabdominal cavity for retrieving gallstones and tissue. The bag is openedand closed using a wire loop as a drawstring. In U.S. Pat. No. 5,192,284an expandable bag is inserted into the abdominal cavity through a trocarcannula. The bag described in the '284 patent is made of a memorymaterial that is rigid enough to support itself. The bag expands andremains open when it is inserted into the abdominal cavity through thecannula. U.S. Pat. No. 5,480,404 describes a pouch for extracting tissuethat is opened and closed by a ratchet mechanism. U.S. Pat. No.5,341,815 employs shape memory effect metal to open the bag uponinsertion through a trocar. U.S. Pat. Nos. 5,681,324 and 5,971,995describe similar bags and pouches.

The pouches described in these patents are useful in containing any bileor gallstones that might otherwise spill into the abdominal cavityduring extraction of a torn gallbladder. These types of devices,however, suffer from at least three problems. Since such devices areclosed on the distal end, air inside the enclosure tends to balloon thepouches or bags during the extraction process thereby increasing thesize or not allowing a full collapse of a bag as it is removed from thewound. Additionally, when the tissue is larger than the wound size, itis forced to the bottom of the bag as the radial force of the wound actson the tissue during extraction. This also increases the size to whichthe wound must be dilated for removal of the tissue. Tapering the bagstoward the distal end helps somewhat to lessen this effect, but theresult is not optimal and does not fully address the problem of airtrapped in the bag. Finally, the work required to remove a gall bladderis equal to the extraction force times the distance over which the forceis required to act plus any heat generated by friction. For example thework required to remove a bagged gallbladder with a 30 mm diameter stoneis the same as the work required to extract the same gall bladder thatis contained in a rigid shallow cone with a maximum diameter of 30 mm(neglecting friction differences). The peak force for removal is muchhigher, however, for the bagged gallbladder since the force is requiredto act over a much smaller distance. Since it is desirable to minimizethe forces required to extract a gallbladder owing to material and humanlimitations, the gallbladder should be, by way of example only,contained in a rigid shallow cone rather than a flexible bag.

Since the goal of laparoscopic surgery is to become less invasive byusing smaller entry wounds, the prior art is of limited value forremoving large specimens through, for example, 5 mm wounds. When theuser pulls on the bag in an attempt to remove it through a small trocarentry wound, the specimen is forced to the bottom of the bag by theradial forces exerted by the abdominal tissue or by the forces exertedon the bag from the cannula, thus creating a large lump that is oftenincapable of passing through the wound without tearing the bag. The useof this type of extraction bag in these cases often requires de-bulkingof the specimen so that the bagged specimen pieces are of such a sizethat the bag can be extracted through the trocar entry wound, typically10-12 mm. This is a time consuming process that is not always successfulsince, for example, large stones may be inside a gallbladder and theprocess usually necessitates the pathologic examination of the tissuespecimen. As an alternative to de-bulking, the wound size may beincreased with a scalpel to allow the extraction. This approach,however, lessons the advantage of the laparoscopic surgery.Additionally, these types of extraction bags add undue complexity to theprocedure since they require the use of two ports, one for the bag and asecond for a grasper to retrieve the tissue and put it into the bag.

U.S. Pat. Nos. 5,190,561 and 5,370,647 to Graber disclose severalembodiments of laparoscopic extraction devices that allow a grasper tobe inserted into the center of an extractor device so that tissue can bemore easily manipulated into the inside of the extractor. In each of theembodiments the extractor is introduced into the abdominal cavitythrough a specially designed trocar cannula equipped with setscrews tolock the extractor to the trocar cannula. Upon exiting the distal end ofthe cannula, the distal end of the extractor expands, much like anumbrella. A grasper is then introduced into the abdominal cavity througha lumen in the extractor. The specimen is grasped and pulled into theexpanded open distal end of the extractor, a cone-shaped device. Thegrasper is then locked to the cannula using the setscrews. The proximalend of the extractor is equipped with a handle, which is used to pullthe extractor and the tissue through the cannula. As the handle ispulled upward “. . . the enveloping means collapses around the tissueand returns to its pre-deployment.” The enveloping means of Graber '647is relied on to compress the tissue to a size that allows it to be drawninto a hollow tubular shroud 610 (see FIG. 13 of Graber '647). Thus, thedevice is not optimally designed to deal with a tissue specimen thatwill not compress to a point so that it can be drawn into the shroud.

The extractor of Graber '647 also has several other disadvantages. TheGraber '647 device is ill-suited for use with standard trocars becauseit utilizes setscrews, which are not generally available on trocars incurrent use, to lock it to the trocar. The Graber '647 device alsoutilizes an expensive locking mechanism to lock the grasper to theextractor. In addition, most abdominal laparoscopic procedures areperformed with the abdominal cavity insufflated with carbon dioxide. Thelumen in the extractor of Graber '647 has no provision for sealing andthus when the extractor is placed through the seal of the trocar, theabdomen will loose its carbon dioxide pressure through the lumen of theextractor.

The Graber '647 device is removed from the body cavity by an exertionforce on the handle of the device. This unduly places rotational andshear forces on the extractor-grasper lever lock and theextractor-trocar setscrews because of the vigorous rotationalmanipulation required to remove it from the abdominal wall.

One of the extractor covers disclosed in the Graber '647 patent is madefrom “a sturdy waterproof, stain resistant fabric such as treatedsailcloth or duck cloth.” These materials are thick, bulky, andgenerally not suited for extractors for use with less invasive trocarcannula such as 5 mm and smaller devices. In particular, such coversrequire multiple folds in order for the extractor to pass through asmall-bore cannula. FIG. 24 of the Graber '647 patent discloses a thin“baggie,” however, it requires thick leaves 608 and a plunger rod 606 tocompress the tissue. The combination and thickness of these features isunduly complicating and makes the Graber device ill-suited for smallcannulas.

The embodiment disclosed in FIG. 12 of the Graber '647 patent teachesthe use of a flexible, waterproof web material with an opening mouth sothat tissue can enter the rib portion 510. While this embodimentpartially solves the spillage problem it unduly complicates manipulatingthe tissue inside the extractor and is overly complex in that theextractor cover and the spillage compartment are made of two separatepieces which must be joined by sewing, heat treating, or welding.

Graber also discloses a multi-leaf rigid cover that is pinned to ahollow elongated shank. The leaves are rolled into a generallycylindrical shape inside the shank in an un-deployed state and expandedinto a generally conical shape in a deployed state. An extractiondilation device having a single leaf is desirable owing to itssimplicity. Graber does not teach a method or mechanism for attaching asingle leaf to the shank since fixedly pinning a single-leaf sheet tothe shank results in buckling of the cone when attempting to roll itinto a generally cylindrical shape for insertion within a tube.

Laparoscopic removal of the gallbladder has, heretofore, entailed theuse of four entry cannula, typically two of which are 10 to 12 mm indiameter and two of which are 5 mm in diameter. The two 5 mm ports areused to accept instruments such as scissors, graspers, electro-surgeryprobes, and suction/irrigation devices. The 10 to 12 mm ports areemployed to allow the use of instruments such as a 10 mm endoscopeattached to a camera for viewing the surgical field or a clip applierfor ligating vessels and ducts, and to permit the removal of agallbladder following its excision.

In an effort to make the procedure less invasive, 5 mm clip appliershave been developed, such as described by Shipp et al. in U.S. Pat. No.5,858,018, the disclosure of which is incorporated by reference herein.The 5 mm clip applier allows the conversion of one of the two 10 to 12mm ports to a third 5 mm port. The remaining 10 to 12 mm port prior tothis invention has been required to accept 10 mm endoscopes and topermit the removal of the gallbladder, usually through the umbilicusport site. New bright 5 mm endoscopes coupled with more sensitivecameras have been developed that are quite acceptable substitutes forthe prior art camera systems. These developments leave gallbladderremoval through a 5 mm or smaller port as the last obstacle to the fullconversion of the process to four much less invasive 5 mm ports. Theconversion from two 10 to 12 mm trocars and two 5 mm trocars to four 5mm trocars lowers the total entry wound area by 50 percent, whichgreatly reduces bleeding and post surgery incisional herniation at thewound sites.

What is needed then is a simple, inexpensive device and an easy to usemethod for rapid removal of tissue, such as a gallbladder, from a woundsite that has an opening size that is smaller than the size of thespecimen and does not require substantial secondary operations such asgrinding the specimen into smaller pieces or significantly enlarging thewound size. Also needed is a simple, rigid single-leaf dilator extractorthat is attached to a hollow shank such that the leaf may easily berolled into a shape exhibiting a minimal diameter for insertion into asmall trocar cannula, for example, 5 mm. Preferably, the deployeddilator extractor is sufficiently rigid so as to provide a smooth,shallow angled cone shape so that the force required to remove thetissue is minimized. Preferably, the dilator extractor isself-deployable to a sufficient base diameter upon exiting the cannula,even after prolonged storage in a rolled-up or un-deployed state.

SUMMARY OF THE INVENTION

The present invention in one embodiment is directed to an expandabledilator extractor that expands upon entry into the abdominal cavity foracceptance of a tissue specimen using a grasper to pull the specimeninto the interior of the dilator extractor. The construction of thedilator is such that when a surgeon places an upward force, away fromthe surface of the abdomen on the deployed dilator, it minimizes thecross section of the tissue by closing a cone about the specimen, andthus minimizes the wound dilation requirement. The resulting elongatedconical shape forces the trocar puncture wound to expand to allow thelarger specimen to be extracted with a minimum of tearing or otherwisepermanently enlarging the wound. The cone angle is minimized to providethe maximum mechanical advantage and thus minimizes the force necessaryfor the surgeon to exert on the device for extraction.

A preferred embodiment of the extractor includes a body having a leadingend, a trailing end, a lumen between the leading and trailing ends, anda mid-longitudinal axis passing through the lumen of the body. Theextractor also includes a dilator at the leading end of the body that ismovable between an unexpanded position and an expanded position. Thedilator has a single leaf adapted to be rolled at least in part aroundthe mid-longitudinal axis of the extractor. The dilator has a guidesurface configured to engage an instrument inserted through the lumen.The guide surface is adapted to move at least a portion of the dilatoraway from the mid-longitudinal axis of the extractor upon engagementwith the instrument.

Another preferred embodiment of the extractor includes a body having aleading end, a trailing end, a lumen between said leading and trailingends, and a mid-longitudinal axis passing through the lumen of the body.The extractor also includes a dilator at the leading end of the bodythat is movable between an unexpanded position and an expanded position.

The extractor also includes a collar that has an opening and is movablerelative to the body along the mid-longitudinal axis of the extractor.The body is adapted to pass through the opening in the collar. Aretainer is attached to the collar. The retainer is adapted to retainthe dilator in the unexpanded position until the body passes through theopening in the collar to move the dilator towards the expanded position.

Another embodiment of the present invention is also directed to asurgical tissue collection bag for removing tissue from an animal orhuman body cavity. The bag includes a top, a bottom, and at least oneside between the top and the bottom. The top has an opening with aperimeter. The bag also includes a resilient expansion member that ismovable between an unexpanded position and an expanded position. Theexpansion member is positioned around at least a portion of the opening.The expansion member is biased toward the expanded position.

Yet another embodiment of the present invention also is directed to amethod for removal of excised tissue with minimal force. The methodincludes providing an extractor having a dilator movable between anunexpanded position and an expanded position. The dilator is made of amaterial that is biased at least in part toward the expanded position.The extractor is inserted through a cannula and at least in part intothe body cavity. The dilator is released to move at least in part towardthe expanded position. A portion of the extractor is engaged with aninstrument to further move the dilator toward the expanded position.Tissue is removed from the body cavity.

In another embodiment the present invention includes a method ofremoving tissue by placing the tissue in a leak-proof bag and insertingthe bagged specimen into a deployed dilator extractor prior toextraction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a grasper, a dilator extractor, and acannula in accordance with one embodiment of the present invention.

FIG. 2 is a partial side sectional view of the dilator extractor of FIG.1 inserted in the cannula of FIG. 1.

FIG. 3 is a partial side elevation view of the leading end of thedilator extractor of FIG. 1 in an expanded position.

FIG. 4 is a bottom plan view along line 4--4 of FIG. 3.

FIG. 5 is a sheet metal layout of the dilator extractor of FIG. 1 priorto being rolled and formed into a conical shape.

FIG. 6 is a perspective view of a dilator extractor in accordance withanother preferred embodiment of the present invention.

FIG. 7A is a perspective view of a tissue collection bag with extensionarms in accordance with another preferred embodiment of the presentinvention.

FIG. 7B is a top view of one of the extension arms of FIG. 7A.

FIG. 8 is a side elevation view of a grasper, dilator extractor, andcannula inserted in the abdominal wall of a patient, the grasper beinginserted in the dilator extractor, the dilator extractor being insertedin the cannula, the dilator extractor and cannula being shown in crosssection with the dilator extractor in the expanded position.

FIG. 9 is a side elevation view of a syringe, grasper, dilatorextractor, and cannula inserted in the abdominal wall of a patient, thegrasper being inserted in the dilator extractor, the dilator extractorbeing inserted in the cannula, the dilator extractor and cannula beingshown in cross section with a tissue specimen being aspirated inaccordance with the instrumentation and method of the present invention.

FIG. 10 is a partial side elevation view of the grasper, dilatorextractor, and cannula of FIG. 9 being withdrawn from the abdominalcavity with the tissue specimen in accordance with the instrumentationand method of the present invention.

FIG. 11 is a side elevation view of a grasper and cannula with anotherembodiment of a dilator extractor of the present invention havingtissue-engaging protrusions being withdrawn from the abdominal cavitywith the tissue specimen.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments (exemplary embodiments) of the invention, examples of whichare illustrated in the accompanying drawings. Wherever possible, thesame reference numbers will be used throughout the drawings to refer tothe same or like parts.

FIG. 1 shows a tool set having a cannula 100, a dilator extractor 200,and a grasper 300. Grasper 300 is insertable in dilator extractor 200,which in turn is insertable in cannula 100 to form a multi-coaxialassembly for use in laparoscopic surgery. An example of a tool setsuitable for use in laparoscopic surgery is described in co-pending U.S.application Ser. No. 10/047,122, filed Jan. 15, 2002, which isincorporated herein by reference.

Referring to FIGS. 2-5 and 8, dilator extractor 200 is inserted into apressurized abdominal cavity 60 through the abdominal wall of a patient.Dilator extractor 200 enters through valve 102 at trailing end 106 ofcannula 100.

Dilator extractor 200 includes a body 202 having a leading end 204, atrailing end 206, a mid-longitudinal axis L, and a lumen 208. Body 202includes a dilator 210 at leading end 204 that is movable between anunexpanded position, shown in FIG. 2, and an expanded position, shown inFIG. 8. Trailing end 206 preferably includes a depth-limiting protrusionin the form of shoulder 207. Shoulder 207 is adapted to limit thedeployment expansion of the cone of dilator 210.

When the trailing end portion of dilator 210 clears leading end 104 ofcannula 100, dilator 210 expands to the expanded position preferablyowing in part to the natural tendency of dilator cone 216 to unroll,thus forming a truncated conical-shaped tissue receiving space 214,enclosed by dilator cone 216.

FIG. 2 shows dilator extractor 200 before dilator 210 clears leading end104 of cannula 100. Dilator 210 may be preserved in the unexpandedposition because of the inner diameter of cannula 100. Dilator cone 216is preferably wrapped upon itself to allow the passage of dilatorextractor 200 in the unexpanded position through cannula 100.

In a preferred embodiment, retainer 218 maintains dilator extractor 200in the unexpanded state. One suitable retainer is straw-shaped andencircles dilator 210. Retainer 218 extends toward trailing end 206 ofdilator extractor 200 terminating into a graspable surface grip 220proximate trailing end 206. The composition of retainer 218 is such thatit is strong enough to restrain the spring forces of dilator 210, yet anupward force on graspable surface grip 220 will cause retainer 218 topeel open allowing dilator 210 to expand. By way of example, a suitablestrength welded seam in a polyurethane film can accomplish such apeeling feature.

In one preferred embodiment a conical section 216 of dilator 210, asbest shown in FIGS. 3-5, is preferably made of a laminated, rigid,material that will allow it to be rolled and contained in cannula 100prior to expansion of dilator 210 of dilator extractor 200. Exemplarymaterials include plastic and metal, such as series 300 stainless steel.Conical section 216 is preferable a single leaf. A single leaf isadvantageous for increasing the strength of conical section 216 as wellas reducing the number of moving parts during the expansion of dilator210.

Conical section 216 includes an inner surface 228 and an outer surface230. Outer surface 230 of dilator cone 216 preferably has a lowcoefficient of friction, such as a PTFE (polytetrafluoroethylene)coating. Inner surface 228 preferably has high coefficient of friction,such as a sand blasted or otherwise roughened surface. It will beappreciated by those skilled in the art that other materials aresuitable for providing a coefficient of friction that is higher on innersurface 228 than outer surface 230 and are within the scope of thepresent invention. Preferably, the coefficient of friction of innersurface 228 is in the range of 0.5 to 1.0. The low friction outersurface 230 of conical section 216 minimizes the force required forextraction while the high friction inner surface 228 provides a grippingforce on the tissue surface area and thereby minimizes the forcetransferred to the grasper/tissue interface during the dilationextraction process. The dilation forces acting on the dilator requirethat the tensile strength of conical section 216 is adequate towithstand the friction force exerted by the tissue on inner surface 228.While a differential coefficient of friction is preferred, the presentinvention is not so limited. For example, inner surface 228 may besmooth.

FIGS. 3 and 4 show dilator 210 in the expanded position. Once dilator210 of dilator extractor 200 is in the expanded position as depicted inFIG. 8, grasper 300, in a preferred embodiment, is inserted throughchannel or lumen 208, into tissue space 214, and into cavity 60.

FIG. 5 shows sheet metal layout of the present invention having conicalsection 216 of a preferably thin, rigid material to which shank 250 isspot welded at locations 254 along a first edge 256 of conical section216. Shank 250 has a proximal end 258 and a distal end 260. Shank 250preferably includes a cut-out portion 262 near proximal end of dilator210. Cut-out portion 262 preferably has a guide surface 252 configuredto contact and interact with grasper 300 to provide force to bend shank250 so that grasper 300 is deployed through the center of conicalsection 216. Cut-out portion 262 assists in permitting shank 250 to bendwhen dilator 210 moves from the un-deployed position to the deployedposition while centering conical section 216 along mid-longitudinal axisL of dilator 200. It is understood that guide surface 252 may be shapedin a variety of ways while still remaining within the scope of thepresent invention. For example, guide surface 252 may be a notch,indentation, projection, or other type of surface irregularity ordeviation configured to interact with an instrument inserted throughbody 202. It is further understood that instead of a shank, the guidesurface may be formed integral with the interior of dilator 210.

Distal end 260 of shank 250 is configured as a key-way to interact witha key used to roll dilator 210 into a generally cylindrical shape sothat first and second edges 256, 264 overlap. Distal end 260 may beangled from the interior of dilator 210 for easier access with the key.

FIG. 6 shows a dilator extractor 200′ in accordance with anotherpreferred embodiment of the present invention. Dilator extractor 200′has a leading end 204′ and a trailing end 206′. Leading end 204′includes a dilator 210′ with a retainer 218′ wrapped therearound.Trailing end 206′ includes a shoulder 207′, a knob 222′, and a portion213′. Located between leading and trailing ends 204′, 206′ is a ring orcollar 209′. Retainer 218′ is preferably attached to ring 209′ at bottomsurface 215′ of ring 209′.

Dilator extractor 200′ is configured so that retainer 218′ is removedduring the insertion of dilator extractor 200′ into cannula 100. Forexample, while inserting dilator extractor 200′ into cannula 100, bottomsurface 215′ of ring 209′ comes into contact with trailing end 106 ofcannula 100. Continued insertion of dilator extractor 200′ into cannula100 causes trailing end 206′ of dilator extractor 200′ to move towardring 209′. Because retainer 218′ remains attached at bottom surface215′, retainer 218′ is removed from dilator 210′ as dilator 210′ isfurther inserted into the cannula. Once dilator 210′ clears leading end104 of cannula 100, dilator 210′ moves into a deployed position.Trailing end 206′ of dilator extractor 200′ continues moving towardsring 209′ until it contacts shoulder 207′. Shoulder 207′ also acts tolimit the depth of insertion of dilator extractor 200′ into cannula 100.Shaft 213′ has an attached cone that is pushed through retainer 218′ soas to fully deploy the cone when shoulder 207′ of knob 222′ meets ring209′. Cannula 100 is stationary. The cone is welded to outside of shaft213′. It is understood that any of the embodiments disclosed herein mayinclude a configuration having a shoulder at the trailing end of thedilator extractor and a collar with a retainer attached thereto so thatas the body is pushed through the retainer, the shoulder of the trailingend of the dilator extractor contacts the collar and the cone deploys.

As shown in FIG. 8, trailing end 206 preferably includes first andsecond seals. The first seal preferably forms a duckbill “V” shapedvalve made of a resilient material that forms a seal when no instrumentis inserted into lumen 208. The second seal is preferably formed of aresilient material containing a through hole in its center. The throughhole is preferably smaller than the maximum cross sectional dimension ofthe instrument that the through hole is adapted to receive and forms aseal when the instrument is inserted into lumen 208. For example, bothseals may preferably be configured to permit the passage of grasper 300therethrough while inhibiting a loss of pressure from within thepatient. It is appreciated that more than or less than two seals may beused without departing from the scope of the present invention.

As shown in FIG. 9, excised tissue 70 is grasped by jaws 310, 312 ofgrasper 300 and pulled inside conical tissue space 214. Once tissue 70is inside conical tissue space 214, the entire assembly (grasper 300,dilator extractor 200, trocar cannula 100, and tissue 70) is ready forextraction.

In instances where the tissue specimen is larger than the insidediameter of cannula 100, such as would usually be the case for agallbladder specimen with a 5 mm cannula for example, dilator 210 willclose somewhat under the influence of the upward force of the surgeonuntil the tissue resilient forces offset the radial forces asserted bythe abdominal wall. At this point conical tissue space 214 of dilatorextractor 200 will no longer contract and grasper 300, dilator extractor200, and cannula 100 will be locked together in a more or less rigidfashion. This condition is depicted in FIG. 10. Dilator extractor 200 isconstructed in such a manner that application of additional force causesthe wedge shape of dilator 210 to begin to increase or dilate the trocarwound in the abdominal wall as the surgeon applies more and more upwardforce. The larger the specimen, the larger the force necessary to dilatethe abdominal wall wound to a size large enough to allow the entireassembly to be removed. The tensile strength of dilator 210 must beadequate to withstand the extraction force. The shape of the trocarpuncture wound is important to insure against tearing of the entrywound. A slit entry wound rather than star-shaped entry wound ispreferred.

Grasper 300, as shown in FIGS. 1 and 8, has a shaft 302 having a leadingend, a trailing end, and a lumen through the center of shaft 302 thatcan be occupied by a needle of a syringe device. Shaft 302 includes jaws310, 312 at the leading end for grasping tissue therebetween. As will beappreciated by those of skill in the art, grasper 300 may be adapted tohave more than two jaws. For example, a third jaw maybe used to providea third grasping surface for grasping the tissue. It will be furtherappreciated that other jaw configurations are possible and within thescope of the present invention. Jaws 310, 312 may have a smooth graspingsurface, or may have ridges.

Shaft 302 preferably has a length in the range of 15 cm to 35 cm and anoutside maximum cross sectional dimension of less than 5 mm. The lumenof shaft 302 preferably has an inside maximum cross sectional dimensionin the range of 1 mm to 4 mm.

As shown in FIG. 8, the trailing end of grasper 300 includes a pair ofhandles 320 for moving jaws 310, 312 relative to one another. Thetrailing end also preferably includes first and second seals. The firstseal preferably forms a duckbill “V” shaped valve made of a resilientmaterial that forms a seal when no instrument is inserted into thelumen. The second seal is preferably formed of a resilient materialcontaining a through hole in its center. The through hole is preferablysmaller than the maximum cross sectional dimension of the instrumentthat the through hole is adapted to receive and forms a seal when theinstrument is inserted into the lumen. For example, both seals maypreferably be configured to permit the passage of a needle therethroughwhile inhibiting a loss of pressure from within the patient. It isappreciated that more than or less than two seals may be used withoutdeparting from the scope of the present invention.

The trailing end preferably includes a depth-limiting protrusion forlimiting the depth of insertion of grasper 300 into the cavity. Thedepth-limiting protrusion may be formed as a shoulder, or may form apart of handles 320.

FIG. 11 shows an alternate embodiment inner surface 228 of conicalsection 216 which is equipped with tissue retaining protrusions such asteeth 234. Preferably, teeth 234 are generally pointed toward trailingend 206 when dilator 210 is in the expanded position so that as dilator210 closes around the tissue as shown in FIG. 11, teeth 234 bite intothe tissue, thus supplying the dominance of the counter acting force tothe extraction force rather than the friction of the tissue againstinner surface 228 of conical section 216. It will be appreciated bythose skilled in the art that teeth 234 may also be included on thesurface of shank 250 if so desired.

It will be appreciated by those skilled in the art that other forms oftissue retaining protrusions are suitable for gripping the tissue, forexample, tabs, ridges, and knurling. Additionally, the tissue retainingprotrusions are preferably uniformly spaced around the longitudinal axisof dilator extractor 200 to provide an even distribution of retainingforce against the tissue. Alternatively, tissue retaining protrusionsmay be positioned on only one side if so desired. Tissue retainingprotrusions may also be spaced substantially about the entire area ofinner surface 228 of conical section 216. Preferably, the tissueretaining protrusions are adapted to grab the tissue without penetratingit in order to reduce the risk of content spillage from the tissue.

Having described the apparatus, methods for its use will now bedescribed. It should be understood that the order disclosed is onlypreferred and that the steps may be performed in other orders whilestill being within the scope of the present invention. Additionally,some steps may be repeated as necessary or omitted.

A preferred method for preparing the dilator extractor for surgical useincludes producing body 202 and dilator 210. Body 202 and dilator 210may be of the same material with a different thickness. Shank 250 isthen attached to body 202. Once dilator 210 and body 202 are assembledtogether, a key is used to engage distal end 260 of shank 250 to winddilator around the mid-longitudinal axis of dilator extractor 200. Oncedilator 210 is sufficiently wound, for example, in a substantiallycylindrical shape, retainer 218 is put onto or wrapped around dilator210 to retain dilator 210 in an unexpanded position. The key is removedfrom distal end

A preferred method of removing tissue from the abdominal cavity is shownin FIGS. 8-10. Cannula 100 is inserted through the abdominal wall andinto cavity 60, which is preferably pressurized. A cannula having amaximum diameter preferably in the range of 3 mm to 5 mm is used inorder to make the procedure less invasive. Dilator extractor 200 isinserted into cannula 100 through seal 102 to a position where leadingend 211 of dilator 210 extends beyond leading end 104 of cannula 100.Dilator 210 is expanded to form tissue extraction space 214. Grasper 300is inserted into dilator extractor 200 through a pair of seals andthrough lumen 208. Shank 250 is bent by the insertion of grasper 300 asshown in FIG. 8 such that grasper 300 extends generally through thecenter of conical section 216 of dilator 210. A portion of grasper 300interacts with shank 250 to cause shank 250 to move away from themid-longitudinal axis of dilator extractor 200. The interaction ofgrasper 300 with shank 250 may occur while grasper 300 is being insertedthrough dilator extractor 200 in a direction substantially parallel tothe mid-longitudinal axis of dilator extractor 200. The tissue isgrasped by grasper 300 and manipulated into tissue space 214. Ifdesired, grasper 300 may be locked to dilator extractor 200 to providemore stability. Next, an upward force is exerted on dilator extractor200, dilating the trocar wound such that the tissue is removed from thecavity under the influence of the upward force. The upward force alsocauses conical section 216 to roll-up, creating a generally evenlydistributed constricting force upon the captured tissue. Theconstricting force greatly reduces the risk of the tissue tearing orrupturing at the grasper/tissue interface.

Alternately, for tissue containing a fluid such as bile in agallbladder, additional steps may be included such as suctioning out thefluid prior to the extraction step. For example, a needle of a syringedevice is inserted into grasper 300 through the seals and through thelumen to a position where the leading end of the needle extends beyondleading end 204 of body 202 of dilator extractor 200. Fluid is thensuctioned from the tissue through the needle by the syringe. It will beappreciated that vacuum sources other than the syringe may be used toaspirate the tissue, for example, an aspirator. It will be furtherappreciated that aspiration may occur during other phases of theoperation prior to the extraction of the tissue from the wound site. Forexample, a needle may be inserted through lumen 208 of dilator extractor200 and fluid suctioned from the tissue before grasper 300 is insertedor used.

To further reduce the extraction force needed to withdraw the assemblywith the tissue, the tissue may be treated to at least partiallydissolve the tissue or its contents, for example, gallstones of agallbladder. A syringe may be used to inject a composition capable ofdissolving tissue. One example of such a composition is methylCert-butyl ether. The tissue is treated preferably after fluid issuctioned. It will be appreciated that the tissue may be treatedirrespective of any fluid suction.

Simulated dilator extractors were built and tested in the abdominalcavity of a swine. Aluminum cones of varying base diameters representingvarying tissue sizes simulated the dilator section. Abdominal access forthe cones was gained through a 100 mm incision along the midline of theanimal. A 5 mm trocar with a single sided cutting tip obturator (ratherthan the more common three side pyramidal tip) was used to entry thecavity through a circular 5 mm wound located approximately 30 mm to theleft of the midline. Each of four simulators consisting of 5 mmcylinders, 100 mm long transitioning into truncated cones with 5 mmdiameter tops tapering to bases of 15, 20, 25, 30 mm diametersrespectively, were separately tested by inserting them through theaccess incision. The 5 mm trocar was then inserted into the abdominalcavity, the obturator removed, and the 5 mm simulator tops were theninserted from the distal of the cannula so that they were exposed abovethe cannula valve. A force gage was then attached to the exposedsection. The vertical pull force required to dilate the 5 mm puncturewound so that the cone was total extracted from the animal was thenmeasured with a calibrated force gage. A new 5 mm trocar site was usedfor each of the four cones. The extraction force is shown in the tablebelow:

Cone Base Diameter, mm Upward Extraction Force, lbs 15 12 20 21 25 37 3050

Each measurement was repeated using the same puncture wound to test theextent to which the wound had been torn or permanently stretched. Thedata indicated that dilation of 2 to 3 times is possible. In ranges upto 20-25 mm, the forces are of reasonable magnitude to make the devicepractical. Minimizing wound size is important to minimizingpostoperative hernias and other complications.

FIG. 7A shows a tissue collection bag in accordance with anotherpreferred embodiment of the present invention generally referred to bythe number 400. Bag 400 includes a top 402, a bottom 404, a first side406, a second side 408 and an interior 410. First and second sides 406,408 are preferably heat welded together along interfaces 412, 414. Bag400 is preferably made of a flexible material such as polyurethane. Top402 includes a hem 416. Hem 416 is preferably heat-sealed and configuredto receive an expansion member 418 at each juncture of first and secondsides 406, 408.

Expansion member 418 includes a bend preferably in the form of a torsioncoil with an arm 420 at each end of coil 422. Coil 422 preferably hasbetween one to four turns, though the invention is not so limited. In adeployed position, arms 420 have an included angle therebetween ofapproximately 120 degrees. As will be appreciated by others of ordinaryskill in the art, arms 420 may be biased to open at other angles greateror less than 120 degrees, such as 45 degrees or 90 degrees. Expansionmember 418 may also have more than two arms, for example, a third armdepending downwardly towards bottom 404 of bag 400. The bend and anyarms associated therewith may be made of a shape memory material.

Preferably an eyelet 424 is formed on the top of expansion member 418.Eyelet 424 is configured for grasping by an instrument such as grasper300. Eyelet 424 preferably has an opening 426 to permit a thread or wireto be inserted therethrough to aid in closing bag 400. The thread mayextend within hem 416 and through eyelet 424, through only eyelet 424,or through hem 416 alone. Other features for closing bag 400 may beused, for example, a press-seal such as found on sandwich bags.

In use, bag 400 is inserted through a cannula in an undeployed positionwith a retainer wrapped therearound in a generally cylindricalconfiguration in a similar fashion to dilator extractor 200. Onceinserted into the cavity of the patient, bag 400 is deployed andexpansion arms 420 are released to open top 402 of bag 400. A grasper isused to manipulate tissue into bag 400. Once the tissue is inside bag400, the eyelets are held by a grasper and the bag extracted from thecavity. Before extracting bag 400 from the cavity, a thread or wire maybe inserted through opening 426 of each eyelet and pulled to provide abetter seal of top 402.

Bag 400 may be inserted and deployed without any attached link such as ahandle or wire remaining outside the cavity. Such a configuration isadvantageous when used in combination with a dilator extractor as thedilator extractor may be used to withdraw a relatively large tissuespecimen through a small incision with little risk of leakage. Bag 400may be shaped to have a generally conical cross section when deployedfor ease of extraction via dilator extractor 200.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. For example only, the guide surface may alsobe configured to align the dilator cone with the mid-longitudinal axisof the dilator extractor when an instrument is inserted into the dilatorextractor. It is intended that the specification and examples beconsidered as exemplary only.

What is claimed is:
 1. A surgical tissue collection bag for removingtissue from an animal or human body cavity, said bag comprising: a top,a bottom, and at least one side between said top and said bottom, saidtop having an opening with a perimeter; and a resilient expansion membermovable between an unexpanded position and an expanded position, saidexpansion member being positioned around at least a portion of saidopening, said expansion member being biased toward the expandedposition.
 2. The bag of claim 1, wherein said expansion member is formedof a single material configured as a loop adapted to extend around theperimeter of said opening of said top.
 3. The bag of claim 2, whereinsaid loop includes two generally opposed coils, each of said coilshaving at least one turn.
 4. The bag of claim 1, wherein said expansionmember includes two arms and a bend therebetween, said bend being biasedto move said arms away from each other.
 5. The bag of claim 4, whereinsaid bend is a coil.
 6. The bag of claim 4, further comprising a secondexpansion member positioned around at least a portion of said openingsubstantially opposite said expansion member.
 7. The bag of claim 6,wherein said opening is generally non-circular when said expansionmembers are in the expanded position.
 8. The bag of claim 4, whereinsaid arms have an included angle therebetween of approximately 120degrees in the expanded position.
 9. The bag of claim 4, wherein saidarms have an included angle therebetween of approximately 90 degrees inthe expanded position.
 10. The bag of claim 4, wherein said arms have anincluded angle therebetween of approximately 45 degrees in the expandedposition.
 11. The bag of claim 4, further comprising a third arm adaptedto depend downwardly towards said bottom of said bag when said expansionmember is engaged thereto.
 12. The bag of claim 1, wherein saidexpansion member comprises a shape memory material.
 13. The bag of claim1, wherein said expansion member includes an eyelet having an openingadapted to permit insertion of a thread or wire therethrough.
 14. Thebag of claim 1, wherein said bag includes a press seal adapted to sealclose said bag.
 15. The bag of claim 1, wherein said bag has a generallyconical cross section along the height of said bag.
 16. The bag of claim1, wherein said bag comprises polyurethane.
 17. The bag of claim 1,wherein said bag comprises a hem for receiving at least a portion ofsaid expansion member.
 18. The bag of claim 17, wherein said hem isheat-sealed.
 19. The bag of claim 1, wherein said bag comprises twosides, said sides being heat-welded together.
 20. The bag of claim 1,wherein said bag has a volume adapted to transport a gall bladder.